Calendar watch with an instantaneous date-change motion

ABSTRACT

1,131,205. Date indicators. ETA A.G. EBAUCHES-FABRIK. Feb.4, 1966 [April 20, 1965], No.4965/66. Heading G3T. A calendar watch possessing an instantaneous date changing motion comprises a date indicating ring 7, capable of being driven by the watch movement and an entrainment member 9 carried by a driving spring 8 and operatively engaging the date indicating ring, the driving spring being mounted on a control wheel 5. The control wheel 5 is continuously driven by an hour wheel 2 via a reduction gear 6. The entrainment member 9 engages a tooth 10 of the date ring 7 so that as the wheel 5 rotates, the spring 8 tensions until the entrainment member reaches a rigid portion 20 of a hub 17 which is an integral part of the wheel 5. The force exerted by the spring on the tooth 10 then causes a detent 12, biased by a spring 15, to move out of engagement with another tooth and thereby allow the entrainment member 9 to advance the date ring 7. Reverse indexing of the date ring 7 during backward setting of the ravels is prevented by a cam surface 21 which pulls the entrainment member 9 out of engagement with the teeth 10.

Nov. 14, 1967 u. GIGER 3,352,103

CALENDAR WATCH WITH AN INSTANTANEOUS DATE-CHANGE MOTION Filed Oct 18, 1965 3 Sheets-Sheet 1 :nvewom Uas. i '5 5).

.8 (J'owm Nov. 14, 1967 u. GIGER 3,352,103

CALENDAR WATCH WITH AN INSTANTANEOUS DATE-CHANGE MOTION Filed Oct. 18, 1965 3 Sheets-Sheet 2 Maw Nqv. 14,1967 v U.IGIGER 4 3,352,103

Filed Oct. 18, 1965 CALENDAR WATCH WITH AN INST A NTANEOUS' DATE-CHANGE MOTION .IN'iNn U3 5:

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3 Sheeis-Sheet 5 Y United States Patent 3,352,103 CALENDAR WATCH WITH AN INSTANTANEOUS DATE-CHANGE MOTION Urs Giger, Solothurn, Switzerland, assignor to Eta A.G. Ebanches-Falirik, Grenchen, Solothurn, Switzeriand, a company limited by shares of Switzerland Filed Oct. 18, 1965, Ser. No. 497,217 Claims priority, application Switzerland, Apr. 20, 1965, 5,462/ 65 4 Claims. (CI. 58-58) The present invention has reference to an improved calender watch with an instantaneous date-change motion in which a driving spring is first tensioned by means or a date indicator control wheel continuously driven by the movement while the date indicator is at standstill and then effectuates a sudden advancing movement of this date indicator by actuating an entrainment means.

In comparison with calendar watches with slower date change motion carried out by means of an entrainment member constructed as a pin and embedded in a date indicator driving wheel, the known calendar watches with an instantaneously jumping date indicator possess a larger number of elements which not only have to be separately manufactured but must also be'separately arranged in the movement. This is especially truefor the entrainment means and the date indicator driving spring which have to be mounted in the movement with the associated fastening-, supportand guide-elements. Consequently, not only is the assembly of a calendar watch with an instantaneous date-change motion more diflicult in comparison with the known, usual calendar watches with slow datechange motion, but furthermore, space requirements are also increased. Even if, on the one hand, the additional structural elements such as, for instance, the driving spring, the entrainment member and the associated fastening-, support-, and guide-elements and, on the other hand, the remaining elements required for carrying out changing of the date, are not arranged in superimposed fashion, rather in juxtapositioned relationship and thus do not directly require any additional structural height, nonetheless for all of the elements which are associated with the date-change operation such an enlarged portion of the surface of the movement base-plate is covered that the relevant elements can no longer be accommodated in recesses of the movement base-plate, rather must be arranged thereabove, so that in the end'elfect there is nevertheless required an additional structural height for the relevant elements.

Accordingly, it is a primary object of the present invention to provide an improved construction of calendar watch of the type described wherein its structural components do not require any more space than those of a simple calendar watch with slow date-change.

Another, more specific object of this invention concerns itself with the construction of an improved calendar watch having an instantaneous date-change motion wherein the components for carrying out the date-change operation require relatively little space, so that the watch still possesses a neat, compact appearance while guaranteeing for a high degree of accuracy and efiiciency in the datechange operation.

In order to implement these and still further objects of the invention which will become apparent as the description proceeds, the invention contemplates providing a calendar Watch in which the date indicator driving spring is seated upon the date indicator control wheel and carries the entrainment means. As a result, the additional elements required for an instantaneous date-change motion first of all, together with the date indicator control wheel which corresponds to the date indicator driving wheel of the usual calendar watches having slow datechange, form a single structural unit. Furthermore, it is 3,352,103 Patented Nov. 14, 1967 ICC possible to mount the driving spring and the entrainment means carried by it upon the date indicator control wheel without requiring a greater structural height than for the entrainment member constructed as a pin and embedded in the date indicator driving wheel in the case of usual calendar watches with slow date-change motion.

Other features, objects and advantages of the invention will becomeapparent by reference to the following detailed description and drawings in which:

FIGURE 1 is a top plan view schematically illustrating a preferred embodiment of inventive device as viewed from the dial side of the movement and depicts the start of the date-change motion;

FIGURE 2 is a top plan view, similar to FIGURE 1, yet depicting the position of the components of the inventive device directly prior to changing the date; and

FIGURE 3 is a top plan view, similar to the previous FIGURES, showing the position of the components during carrying out a correction of the date indicator.

Describing now the drawings, it is to be understood that the exemplary illustrated embodiment of inventive apparatus of calendar watch only depicts enough of the structural components or elements which are thought necessary to understand the principles of the invention. This calendar watch W comprises a conventional motion work having a cannon pinion 1, an hour wheel 2, a minute wheel 3 and a hand-setting wheel 4. In order to enable the date to be changed this watch W further possesses a date indicator control wheel 5 which is continuously driven by the hour wheel 2 through the agency of a speedreduction gear 6 and carries out one revolution in twentyfour hours. Serving as the date indicator is a standard date ring 7 which is mounted in known manner on the movement. This date ring 7 is step-wise and instantaneously advanced once during each revolution of the date indicator control wheel 5, by means of a driving spring 8 seated upon control wheel 5 and an entrainment member 9 carried by this driving spring 8. For this purpose, the entrainment member 9 comes into engagement with an inner toothing 10a possessing individual spaced teeth 10 and provided at the date ring 7. Thus at the beginning of the switching operation the entrainment member 9 comes to bear against a tooth 10 of this date ring 7 (FIG- URE 1). Upon continued rotation of the control wheel 5 in the direction of the arrow a the date ring 7 is not immediately entrained however. On the contrary, the driving spring 8 is first gradually tensioned while the date ring 7 is at standstill.

During this first preparatory phase of the aforementioned date-change motion the date ring 7 is fixedly held by a spring-loaded detent 12. This detent 12 is mounted upon the movement for rotation about a journal pin 13 and is axially fixedly restrained by means of a cover plate 14 connected via a screw 11 to the movement bridge of the movement. As soon as the entrainment member 9, under the driving action of the control wheel 5, overcomes the blocking action exerted upon the date ring 7 due to engagement therewith of the detent 12 occuring under the action of the spring 15, then the date ring 7 is released by the detent 12, and due to the action of the previously tensioned driving spring 8 and the entrainment member 9 carried by the latter is suddenly advanced by one step.

As readily apparent by referring to the drawings, the driving spring 8 possessing the entrainment member 9 and a hub or nave 17, seated upon the shaft 16 of the control wheel 5, is formed of one piece. The control wheel 5 and a cover plate 18 likewise seated upon the shaft 16 limit the play of the entrainment member 9 in axial direction to such an extent that the latter can neither move above nor below past the teeth 10 of the date ring 7.

It should thus be apparent that the control wheel 5,

the driving spring 8 and the entrainment member 9 form a single structural unit which does not require any greater space in elevation than the corresponding date indicator driving wheel with embedded entrainment pin of the known, usual calendar watches having slow date-change motion. In comparison with the relevant known date indicator driving wheel the control wheel 5 of the inventive calendar watch W can be of thinner construction because no entrainment pin is embedded in the latter and, furthermore, the entrainment member 9 with associated driving spring 8 as well as the cover plate 18 can be accommodated in the same space as the entrainment pin for the relevant known calendar watches.

So that the advancing movement of the date ring 7 takes place at the same time each day, the flanks of the teeth of the aforesaid ring and the rear flank 19 of the detent 12 counteracting the advancing movement of the date ring 7 are advantageously directed such that they enclose a small angle with the movement radius passing through this flank 19. Due to this measure the detent 12 only then comes out of engagement, even when using a weak spring 15, when the date ring 7 is driven by a relatively large force. In order to exert such a force upon the date ring 7 the driving spring 8 alone is insufl'icient. Accordingly, the hub 17 additionally possesses a rigid portion 20 which, at the end of the first phase of the advancing movement i.e. when the driving spring 8 is fully tensioned, bears upon the entrainment member 9. Since this rigid portion 20 is fixedly connected with the control wheel 5, the entrainment member 9 is positively or force-locking connected by such portion 20 with the aforesaid control wheel 5 at the moment depicted in FIGURE so that the date ring 7 is then forcibly released at the prescribed time from the detent 12.

In conjunction with this releasing operation there is incidentally remarked that the function of the watch W is not disturbed due to an unintentional breakdown of the blocking action of the detent 12, for instance due to wear of either the teeth 10 of the date ring 7 or the flank 19 of the detent 12 or, in fact, due to an improper co-ordination of the forces of the springs 8 and 15. In such case, there is only lost the feautre of the date-changing capability of the watch occurring instantaneously. In other words, the watch will run equally well and the changing of the date will take place in the manner of calendar watches operating with slow date-change motion.

-It will also be observed that a camming surface 21 is located at the hub 17 and, as shown in FIGURE 3, cooperates with the entrainment member 9 to prevent a reverse switching or indexing of the date ring -7 when the hands of the watch are set backwards. The camming surface 21 is inclined for this purpose in such a manner that it pulls the entrainment member 9 out of the teeth 10 of the date ring 7 in order to remove its operable engagement with such date ring 7, the latter being locked by the forward locking or blocking flank 22 of the detent 12 when the control wheel 5 is driven in the direction of the arrow b (FIGURE 3) during setting of the hands.

Moreover, due to the camming surface 21 the date ring 7 can be set anew quickly by turning the hands through a few hours forwardly and rearwardly in the usual manner. During each to-and-fro movement of the hands the date ring 7 is then advanced by one step.

The described structure exhibiting the hub 17, the driving spring 8, the entrainment member 9, the portion 20 and the camming surface '21 can be very easily manufactured in a punching operation, and furthermore, can be mounted at least just as easily upon the date indicator control wheel 5 as a conventional entrainment pin. Due to the provided arrangement of the entrainment member 9 4. it is possible to provide the date ring 1 with shorter teeth than exist at calendar watches having a rigid entrainment member.

While there is shown and described a present preferred embodiment of the invention it is to be distinctly understood that the invention is not limited thereto but may be otherwise variously embodied and practised Within the scope of the following claims.

I claim:

1. In a calendar watch having a watch movement and possessing an instantaneous date-change motion, the combination of: a date indicator, a date indicator control wheel capable of being driven by the watch movement, a shaft upon which is mounted said date indicator control wheel, a driving spring cooperating with said date indicator, said driving spring including a hub portion seated upon said shaft, an entrainment member carried by said driving spring engageable with said date indicator, said driving spring being operably mounted upon said date indicator control wheel, said driving spring, said hub portion and said entrainment member being formed of one piece, said date indicator control wheel tensioning said driving spring only when said date indicator is at standstill and then said driving spring brings about forward movement of said date indicator through actuation of said entrainment member, a spring-loaded detent cooperating with said date indicator for temporarily holding the latter in a date-indicating position, a rigid member portion fixedly connected with said date indicator control wheel for operatively connecting said entrainment member with said date indicator control wheel in forcelocking manner when said driving spring is fully tensioned in order to disengage said detent from said date indicator.

2. The combination defined in claim 1, wherein said rigid member portion is constructed as part of said hub portion.

3. In a calendar watch having a watch movement and possessing an instantaneous date-change motion, the combination of: a date indicator, a date indicator control wheel capable of being driven by the watch movement, a shaft upon which is mounted said date indicator control wheel, a driving spring cooperating with said date indicator, said driving spring including a hub portion seated upon said shaft, an entrainment member carried by said driving spring engageable with said date indicator, said driving spring being operably mounted upon said date indicator control wheel, said driving spring, said hub portion and said entrainment member being formed of one piece, said date indicator control wheel tensioning said driving spring only when said date indicator is at standstill and then said driving spring brings about forward movement of said date indicator through actuation of said entrainment member, a camming surface which is stationary relative to said date indicator control wheel, said camming surface cooperating with said entrainment member during backward setting of the watch in order to disengage said entrainment member from said date indicator.

4. The combination as defined in claim 3, wherein said camming surface is situated at a part of said hub portion.

References Cited FOREIGN PATENTS 328,143 4/ 1958 Switzerland.

RICHARD B. WILKINSON, Primary Examiner.

GERALD F. BAKER, Examiner.

MICHAEL LORCH, Assistant Examiner. 

1. IN A CALENDAR WATCH HAVING A WATCH MOVEMENT AND POSSESSING AN INSTANTANEOUS DATE-CHANGE MOTION, THE COMBINATION OF; A DATE INDICATOR, A DATE INDICATOR CONTROL WHEEL CAPABLE OF BEING DRIVEN BY THE WATCH MOVEMENT, A SHAFT UPON WHICH IS MOUNTED SAID DATE INDICATOR CONTROL WHEEL, A DRIVING SPRING CO-OPERATING WITH SAID DATE INDICATOR, SAID DRIVING SPRING INCLUDING A HUB PORTION SEATED UPON SAID SHAFT, AN ENTRAINMENT MEMBER CARRIED BY SAID DRIVING SPRING ENGAGEABLE WITH SAID DATE INDICATOR, SAID DRIVING SPRING BEING OPERABLY MOUNTED UPON SAID DATE INDICATOR CONTROL WHEEL, SAID DRIVING SPRING, SAID HUB PORITON AND SAID ENTRAINMENT MEMBER BEING FORMED OF ONE PIECE, SAID DATE INDICATOR CONTROL WHEEL TENSIONING SAID DRIVING SPRING ONLY WHEN SAID DATE INDICATOR IS AT STANDSTILL AND THEN SAID DRIVING BRINGS ABOUT FORWARD 